Here, the 'dummy' GOS command loads a file and puts its size into the given variable. And the locations 56331-56328 are the TOD clock locations. Clock starts when you poke a value to 56328 (tenth of second).

So, this test shows that the random disk speed is 1909 Bps with a 40% cache hit rate. This figure includes the directory lookup of the files, the random seeks (which are eliminated by 40%) and the decompressions of the blocks. Not bad for a 19 years old cache I think.